ref: 1e773c97e79d74983edd9b46694956f76b0c7fd5
dir: /sys/src/ape/lib/v/nrand.c/
#include <stdlib.h>
#define MASK 0x7FFFFFFFL
#define FRACT (1.0 / (MASK + 1.0))
extern long lrand(void);
double
frand(void)
{
return lrand() * FRACT;
}
nrand(int n)
{
long slop, v;
slop = MASK % n;
do
v = lrand();
while(v <= slop);
return v % n;
}